This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. TRF2 is an essential gene that localizes to telomeres and is required for chromosome end protection. TRF2 binds to double stranded telomeric repeats (TTAGGG) and serves as an anchoring protein required to recruit additional factors. Recent data suggest that over 200 proteins are bound at telomeres.